No-Heparin Patients - Bolus vs. Constant Infusion NS

[happybunny1970]

I work in an Acute unit and we are revisting and rewriting some of our protocols. Of particular concern is the clotting of systems due to "no heparin" orders -- most often this is justified because we may have surgical patients or those with GI bleeds, etc, so it's not a problem with a physician having some crazy anti-heparin agenda. The concerns are two fold: Each clotted system deprives the patient of about 300cc of their own blood, and of course they can't afford to be losing blood at each dialysis treatment. Practically, of course, there is also the cost involved in resets and clotted dialyzers.

One of our charge nurses instituted a system of flushing a 'no-heparin' patient with 150cc NS Q30min (with the flushes added to the UF Goal, so what we are giving is taken off in the end). The results have been promising thus far, and we haven't lost a circuit yet (after a few weeks).

So we got to talking about CRRT, which we set up and tear down, but which are maintained by ICU staff. When a patient is on CRRT, the nurse:patient ratio is supposed to be 1:1, and most often is, so one wouldn't expect clotting to be a problem, since with only one patient it is logical to expect the nurse to be pretty close to the bedside most of the time, and able to keep an eye on things. (When we do regular dialysis treatments in the ICUs, our dialysis nurse SITS at the bedside for the duration of the treatment, except for maybe a quick relief for a bathroom break). But it seems to happen quite a bit still, and moreso at night than during the day.

So I posited a question: Wouldn't it be logical that there would be some sort of unit we could employ that would deliver boluses, which we could program with a specific amount and at timed intervals? Another nurse mentioned that we could hook up a regular pump and set it at 150cc/hr to give a continuous infusion. But my question is, when the goal is to flush the dialyzer in absence of heparin to prevent clotting, is it better to give a good-sized bolus or give a continuous infusion? I sort of think the boluses do a better job, plus they clear the lines so you can sneak a peek at any current clot formation.

Thoughts?

[DeLana_RN, BSN, RN]

Hi,

I know what you mean about the no heparin tx's, we have quite a few of those in my acute unit. Our protocol calls for priming the system with an NS bag that has 5000 U of heparin added to it; I have to add that we normally don't give the prime (judgement call if BP is fairly low). In addition, you should give NS 100 cc q 30 min as a bolus. I really don't think a continuous infusion would do any good, since you're trying to flush the system (and look for clots as well).

Amazingly, some of my much more experienced colleagues don't believe in doing these interventions; one, whom I normally respect very much, acutally believes that the boluses cause clotting (sorry, I have to disagree! This makes no sense). Many have a rather nonchalant attitude toward clotted systems which, again, I cannot share (as you said, often you have to dump the blood, something renal pts can ill afford). Some even refuse to give heparin the MD has ordered (we can use our judgement, yes, but unless I see something glaring that the doc must have overlooked, I would never do that).

We don't do CRRT, so dialysis nurses do all acute tx's (1:1 ratio, or course). I have had very few clotted systems, so the saline flush protocol seems to work (it appears that I'm the only one who uses it, not always q 30 min, but certainly if I see the need! Some pts truly don't need the flushes, but again, this can be nursing judgement).

HTH,

DeLana

P.S. We recently had a GI bleeder who clotted more systems than I have ever seen (and we had to keep giving him PRBCs, mostly for the Gl bleeds, of course, but we surely contributed.) Nothing helped, not heparin prime, nor frequent flushes... after two clotted systems per tx we usually gave up (he must have had an unusual clotting disorder!)

[happybunny1970]

Thanks, DeLana...

I hear you. One of the things I love about this job is the technical aspect and the latitude in nursing judgment calls. I've had only one clotted system in the 8 months I've been in the unit, and that one in the last 10 min of tx -- totally freaky, just an all-of-a-sudden thing, don't think there's anything I could have done differently. I do know of a patient or two who I haven't personally treated that have some freaky clotting disorders who ALWAYS clot a system... guess one day they'll spoil my record...

We also have a couple of nurses who, though I love them all dearly, are 'set in their ways' and don't want to change their protocols. I figure we each have our own responsibilities and our own patient load, so I let them do their thing without incident, but if I'm teamed with them for a day (we try to have 2 nurses, 1 tech per bay of 5 beds), and I happen to get to the patient first at the 1/2 hour checks... well... chances are they're gonna get a flush!

[Dialysister]

I find that if I have a blood flow rate of at least 400, a 50cc NSS bolus every 30 minutes is sufficient to prevent clotting. If the blood flow is slower, I give a 100 cc bolus every 30 minutes. These are just guidelines, though. I keep an eye on my venous pressure and if it's creeping up I may give a little flush. I do add in the added saline to my target loss. Had a patient today with hemoptysis and the 50cc/30 minutes worked great without running any heparin at all.

[bluefabian]

Work in chronic dialysis.

For pt just undergoing any operation of any kind, I usually deliver the first bolus dose and follow up with saline flushes every 30 mins or so. This usually does the trick versus the no heparin policy - of which the dialyzer will clot for sure, saline flush or not.

Bolus dose alone will not cut it - I just did one today. While the entire blood line runs OK until the end, a few fibers of the dialyzer was blocked.

I guess you all know this already - moving blood has little tendency to clot even for those with very fast clotting time. I've seen a few instances where the whole system were jammed just because of a few seconds of needle adjustment. Learned my lesson and will always recirculate during difficult re-cannulation.